METALLOGRAPHIC STANDARDS 

OF THE BUREAU OF STEAM ENGINEERING 

FOR 

STEEL FORGINGS 


ISSUED BY THE NAVY DEPARTMENT 
JANUARY 2, 1917 


To be used in connection with the latest 
edition of the specifications for steel forgings 
issued by the Navy Department (49-S-2) 



WASHINGTON 

GOVERNMENT PRINTING OFFICE 
1917 










METALLOGRAPHIC STANDARDS 

OF THE BUREAU OF STEAM ENGINEERING 

A 

FOR 

STEEL FORGINGS 


ISSUED BY THE NAVY DEPARTMENT 
JANUARY 2, 1917 


^1 To be used in connection with the latest 
edition of the specifications for steel forgings 
issued by the Navy Department (49-S-2) 



WASHINGTON 

GOVERNMENT PRINTING OFFICE 
1917 









D„ of D. 

APR !g 1917 






METALLOGRAPHIC STANDARDS 


Vv 


l 




OF THE 

BUREAU OF STEAM ENGINEERING 

FOR 

STEEL FORGINGS. 


The illustrations contained in this pamphlet compose the metallo- 
graphic standards of the Bureau of Steam Engineering for various classes 
of steel. They illustrate structures which are acceptable and unaccept¬ 
able to the Bureau of Steam Engineering according to whether they do 
or do not conform to the metallographic requirements included in the 
specifications for steel forgings. 

All the specimens from which the photographs were taken were etched 
with picric acid, and the illustration is reproduced from the photograph 
and represents the structure at a magnification of 100. The photographs 
were all taken by arc light, the eyepiece used was a 10-power, the objec¬ 
tive 10 mm., and the exposure 2 seconds. 

REFERENCE: 

S. E. 206326-710-S, Nov. 25, 1916. 

S. & A., 380-789. 


( 3 ) 




Test No. 582. Card No. 8. Inclosure ( H ). 
CHEMICAL ANALYSIS. 


c | s 

Mn 

Si 

P 

Cr 

V 

.37 .023 

.56 

.158 

.010 

.99 

.17 


PHYSICAL TESTS. 




Elongation 

Per cent 
reduction. 


Tensile strength. 

Yield point. 

(per cent in 

2 inches). 

Bend. 

109500 

107000 

22 

65.2 

O. K. 


The above illustration represents a structure which is desired by the 
Bureau of Steam Engineering for class alloy steel forgings. 

Heat treatment .—The structure represented was obtained by oil quench¬ 
ing followed by annealing. 

The white areas represent ferrite. The black areas represent sorbitic 
pearlite. 

This specimen was taken from a crank-shaft forging. The grain size is 
unusually fine. 


( 4 ) 




































Test No. 582. Card No. 5. Inclosure ( E). 
CHEMICAL ANALYSIS. 


c 

s 

Mn 

Si 

P 

Cr 

V 

CO 

1 

co 

O 

.56 

.158 

.010 

.99 

.17 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

111840 

108580 

22.8 

64.04 

O. K. 


The above illustration represents a structure which is acceptable to the 
Bureau of Steam Engineering for class alloy steel forgings. 

Heat treatment .—The structure represented was obtained by oil quench¬ 
ing followed by annealing. 

The white areas represent ferrite. The black areas represent sorbitic 
pearlite. 

This specimen was taken from a crank-shaft forging. Though the grain 
size is moderate, a finer structure could be obtained with this class of 
material. 


( 5 ) 






























Test No. 393. Card No. 6. Inclosure (F). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 

_1 

1 

.28 

.027 

. 53 

. 160 

.008 

.78 | .18 


PHYSICAL TESTS. 


Tensile strength. 


Elongation 

Per cent 
reduction. 


Yield point. 

(per cent in 

2 inches). 

Bend. 

117000 

107500 

22 

61 

O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for class alloy steel forgings. 

Heat treatment .—The structure represented was obtained by oil quench¬ 
ing followed by annealing. 

The white areas represent ferrite. The halftone areas represent pear- 
lite and sorbite. 

This specimen was taken from a crank-shaft forging for a submarine. 
This structure is nonuniform. In some places the grain size is small and 
there is much free ferrite. In other regions a large grain size is found. 


( 6 ) 

































Test No. 558B. Card No. 1. Inclosure ( A-l). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 

Ni 

.270 

.042 

. 45 

.110 

.027 

3. 33 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

85250 


29.5 

62.43 

O. K. 


The above illustration represents a structure which is desired by the 
Bureau of Steam Engineering for Class An steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 
The white areas represent ferrite. The black areas represent pearlite. 
This specimen was taken from a collar for shafting for a battleship. 
This structure is very fine grained and uniform. 


( 7 ) 



























Test No. 695. Card No. 00. Inclosure (—). 


CHEMICAL ANALYSIS. 


c 

s 

Mn 

Si 

P 

Ni 

.40 

.010 

.62 

.142 

.006 

3.32 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

90000 

51500 

29.0 

52.5 

O. K. 


The above illustration represents a structure which is acceptable to 
the Bureau of Steam Engineering for Class An steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 

The white areas represent ferrite. The black areas represent pearlite. 

This specimen was taken from a line-shaft forging for a battleship. The 
grain size is satisfactory and the structure is free from segregation of ferrite 
and pearlite. 


( 8 ) 
























Test No. 556A. Card No. 13. Inclosure ( E-5). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 

Ni 

. 268 

00 

?o 

o 

. 67 

.163 

.023 

3. 49 


PHYSICAL TESTS. 




Elongation 

Per cent 
reduction. 


Tensile strength. 

Yield point. 

(per cent in 

2 inches). 

Bend. 

89600 

56900 

28.1 

55.3 

O. K. 


The above illustration represents a structure which is acceptable to 
the Bureau of Steam Engineering for Class An steel forgings. 

Heat treatment .—The structure represented was obtained by double 
annealing. 

The white areas represent ferrite. The black areas represent pearlite. 

This specimen was taken from a line-shaft forging for a torpedo-boat 
destroyer. The grain size is moderate. A finer structure, however, 
could be obtained with this class of material. 

(9) 


71795—17-2 
























Test No. 558B. Card No. 8. Inclosure ( C-4 )• 


CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 

Ni 

.290 

.042 

.67 

.165 

.024 

3.62 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

87500 

54300 

27.4 

54.05 

O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for Class An steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 
The white areas represent ferrite. The black areas represent pearlite. 
This specimen was taken from a sleeve coupling for shafting for a 
battleship. The structure is considerably coarser than it should be. 
The grain size exceeds that allowed in the specifications. 


( 10 ) 


























Test No. 511. Card No. 4. Inclosure (D). 
CHEMICAL ANALYSIS. 


c 

s 

Mn 

P 

.50 

.024 

.53 

.015 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

86500 

62500 

31.5 


O. K. 


The above illustration represents a structure which is acceptable to 
the Bureau of Steam Engineering for Class Ac steel forgings. 

Heat treatment .—The structure represented was obtained by oil quench¬ 
ing followed by annealing. 

The white areas represent ferrite. The black areas represent sorbitic 
pearl ite. 

This specimen was taken from a propeller-shaft forging for a battleship. 
The grain size is moderate and the distribution of ferrite and pearlite is 
fairly uniform. 


(H) 

























Test No. 511. Card No. 3. Inclosure (C). 

CHEMICAL ANALYSIS. 


c 

s 

Mn 

p 

.50 

.024 

. 53 

.015 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

80120 

52750 

31.5 

O. K. 


The above illustration represents a structure which is acceptable to 
the Bureau of Steam Engineering for Class Ac steel forgings. 

Heat treatment.— The structure represented was obtained by oil quench¬ 
ing followed by annealing. 

The white areas represent ferrite. The black areas represent sorbitic 
pearl ite. 

This specimen was taken from a propeller-shaft forging for a battleship. 
Though the grains in some places measure about one-half inch in diam¬ 
eter, the structure can be considered acceptable. A finer structure is 
desirable. 


( 12 ) 




























Test No. 675. Card No. 33. Inclosure ( N-l). 
CHEMICAL ANALYSIS. 



c 

S 

Mn 

Si 

P 


.43 

.027 

.53 

.137 

.004 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent . 
reduction. 

Bend. 

78900 

42000 

28.2 

47.4 

O. K. 


The above illustration represents a structure which is acceptable to 
the Bureau of Steam Engineering for class B special steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 
The white areas represent ferrite. The black areas represent pearlite. 
This specimen was taken from a crank-shaft forging for a submarine. 
The grain size is moderate and the structure is uniform. 


( 13 ) 




























Test No. 675. Card No. 36. Inclosure (N-4). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 

.43 

.027 

.53 

.137 

.004 


PHYSICAL TESTS. 



Yield point. 

Elongation 

Per cent 
reduction. 


Tensile strength. 

(per cent in 

2 inches). 

Bend. 

78900 

42000 

28.2 

47.4 

O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for Class B special steel forgings. 
Heat treatment .—The structure represented was obtained by annealing. 
The white areas represent ferrite. The black areas represent pearlite. 
This specimen was taken from a crank-shaft forging for a submarine. 
This structure is nonuniform. Regions of coarse network are surrounded 
by regions of fine structure. 


( 14 ) 


























Test No. 6381). Card No. 33. Inclosure (Q-2). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 


.32 

.021 

.50 

.145 

.Q 18 



PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

71025 

41425 

35.0 

59.9 

0. K. 


The above illustration represents a structure which is desired by 
the Bureau of Steam Engineering for Class B steel forgings. 

Heat treatment .—The structure represented was obtained by simple 
annealing. 

The white areas represent ferrite. The black areas represent pearlite. 

This specimen was taken from a propeller-shaft forging for a submarine. 
The fine-grained structure, obtained by simple annealing, is evidence 
of what can be accomplished in the heat treatment of Class B steel. 


( 15 ) 

























Test No. 583. Card No. 00. Inc.losure ( ). 

CHEMICAL ANALYSIS. 


c 

S 

Mn 

P 

.38 

.036 

.49 

.014 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

62750 

31750 

30.5 

40.3 

O. K. 


The above illustration represents a structure which is acceptable to 
the Bureau of Steam Engineering for Class B steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 
The white areas represent ferrite. The black areas represent pearlite. 
This specimen was taken from a thrust-shaft forging for a supply ship. 
Size of forging, 26 inches by 20 feet. Though the grain size is larger than 
it should be, the structure is acceptable for this class of steel. 


( 16 ) 
























Test No. 583A. Card No. S. Inclosure (H). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

P 

. 35 

.045 

.40 

.04 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

61750 

32S00 

33.5 

49.4 

O. K. 


The above illustration represents a structure which is acceptable to 
the Bureau of Steam Engineering for class B steel forgings. 

Heat treatment. —The structure represented was obtained by annealing. 
The white areas represent ferrite. The black areas represent pearlite. 
This specimen was taken from an eccentric-rod forging. The structure, 
though not as fine as it should be, is acceptable. 


( 17 ) 























Test No. 444F. Card No. 4. Inclosure (D). 

CHEMICAL ANALYSIS. 


c 

s 

Mn 

p 

.40 

.033 

. 51 

.022 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

1'er cent 
reduction. 

Bend. 

77520 

38070 

27.1 


O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for ('lass B steel forgings. 

Heat treatment .—The structure represented was obtained by oil quench¬ 
ing followed by annealing. 

The white areas represent ferrite. The black areas represent pearlite. 

This specimen was taken from a crank-shaft forging for a torpedo-boat 
destroyer. The large grain size renders this forging unsuitable for use in 
shafting. It has evidently been considerably overheated. 


( 18 ) 



























Test No. 527. Card No. 3. Inclosure (C). 
CHEMICAL ANALYSIS. 



C 

S 

Mn 

p 


.33 

.023 

. 56 

. .012 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

66000 

34000 

30.0 


O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for Class B steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 

The white areas represent ferrite. The black areas represent pearlite. 

This specimen was taken from a 9-inch round bar 20 feet long. Rem¬ 
nants of a very large grain occupy almost the entire field of view. Such 
a coarse triangular structure is known as ingotism. 


( 19 ) 


























Test No. 444C. Card No. 17. Inclosure (Q). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

P 

.33 

.035 

.53 

.010 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

72890 

39300 

30.0 


O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for Class B steel forgings. 

Heat treatment .—The structure represented was obtained bv oil quench¬ 
ing followed by annealing. 

The white areas represent ferrite. The black areas represent sorbitic 
pearlite. 

This specimen was taken from a crank-shaft forging for a submarine. 
Several groups of constituents, which originally formed large austenite 
grains, are here shown. Such a coarse structure is unsuitable for shafting. 


( 20 ) 





























Test No. 583A. Card No. 14- Inclosure (N). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

P 

.35 

. 0*15 


.04 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

61750 

32800 

33.5 

49.4 

O. K. 


The abovei llustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for Class B steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 

The white areas represent ferrite. The black areas represent pearlite. 

This specimen was taken from a piston-rod forging for a transport. The 
broad ferrite streaks, containing segregated particles of manganese sul¬ 
phide, render the forging unsuitable for use in shafting. The grain size 
is also larger than allowed. 


(21 > 






















Test No. 630F. Card No. 14. Inclosure ( G-2 ). 

CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 

.245 

.031 

.513 

.213 

.027 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

68250 

39500 

31.5 

52.3 

O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for Class B steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 

The white areas represent ferrite. The black areas represent pearlite. 

This specimen was taken from a propeller-shaft forging for a submarine. 
This structure is far from homogeneous. Irregular streaks and patches 
of ferrite and pearlite, i. e., decided segregation of the normal constitu¬ 
ents, are here shown. 


( 22 ) 






























Test No. 558B. Card No. 5. Inclosure ( C-l). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 

Ni 

.290 

.042 

.67 

.165 

.024 

3. 62 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

87500 

54300 

27.4 

54.05 

O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for Class An steel forgings. 

Heat treatment .—The structure represented was obtained by annealing. 

The white areas represent ferrite. The black areas represent pearlite. 

This specimen was taken from a sleeve coupling for shafting for a battle¬ 
ship. The structure is not homogeneous. Broad ferrite streaks, such as 
the one here shown, render a forging unsuitable for use in shafting. The 
normal constituents are decidedly segregated. 


( 23 ) 


























Test No. 393C. Card No. 1. Inclosure (A). 
CHEMICAL ANALYSIS. 


c 

S 

Mn 

Si 

P 

Cr 

V 

.28 

.030 

.49 

. 146 

.007 

.70 

.14 


PHYSICAL TESTS. 


Tensile strength. 

Yield point. 

Elongation 
(per cent in 

2 inches). 

Per cent 
reduction. 

Bend. 

115620 

100750 

22.3 

61.1 

O. K. 


The above illustration represents a structure which is not acceptable 
to the Bureau of Steam Engineering for class alloy steel forgings. 

Heat treatment .—The structure represented was obtained by oil quench¬ 
ing followed by annealing. 

The white areas represent ferrite. The black areas represent sorbitic 
pearlite. 

This specimen was taken from a crank-shaft forging for a submarine. 
This structure is not uniform. A large grain size is found in some regions 
while in other regions the grain size is small. 

o 


( 24 ) 


































